Adapted from Wikipedia and Myanimelist.net:

Background: Damekko Doubutsu features characters that wear kigurumi (mascot/animal character) costumes and who seem to be either living as or putting on a play about animal outcasts who must live in the "Useless" Forest due to behaving strangely for their species. For example, the main character, Uruno, is a wolf who has the personality of a shy rabbit; meanwhile, Usahara, a rabbit, acts like a wolf.

Story: Uruno, the shy wolf, is on the road searching for a new place to call home. He soon comes upon a whole forest full of "useless animals": that is, animals that don't live up to their species' usual character.

After a short fight with the smoking, bad-tempered rabbit, Usahara, Uruno decides that he wants to move on... but changes his mind upon meeting Chiiko, a clumsy cheetah girl. It's love at first sight for Uruno, and after deciding to stay for her, he continues to hope that even though he's a good-for-nothing, he'll win her over someday. That is, if living with the other strange residents of the forest— including the aformentioned smoking rabbit, a sake-drinking unicorn, a near-sighted eagle, an orca that cannot swim, and a shy pegasus—doesn't get to him first.

See also:
http://animenewsnetwork.com/encyclopedia/anime.php?id=4994
Official Kids Station site for the anime (in Japanese)